Unlike virtio_balloon/virtio_mem/xen balloon drivers, Hyper-V balloon driver does not adjust managed pages count when ballooning/un-ballooning and this leads to incorrect stats being reported, e.g. unexpected 'free' output. Note, the calculation in post_status() seems to remain correct: ballooned out pages are never 'available' and we manually add dm->num_pages_ballooned to 'commited'. Suggested-by: David Hildenbrand <david@xxxxxxxxxx> Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx> --- drivers/hv/hv_balloon.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c index da3b6bd2367c..8c471823a5af 100644 --- a/drivers/hv/hv_balloon.c +++ b/drivers/hv/hv_balloon.c @@ -1198,6 +1198,7 @@ static void free_balloon_pages(struct hv_dynmem_device *dm, __ClearPageOffline(pg); __free_page(pg); dm->num_pages_ballooned--; + adjust_managed_page_count(pg, 1); } } @@ -1238,8 +1239,10 @@ static unsigned int alloc_balloon_pages(struct hv_dynmem_device *dm, split_page(pg, get_order(alloc_unit << PAGE_SHIFT)); /* mark all pages offline */ - for (j = 0; j < alloc_unit; j++) + for (j = 0; j < alloc_unit; j++) { __SetPageOffline(pg + j); + adjust_managed_page_count(pg + j, -1); + } bl_resp->range_count++; bl_resp->range_array[i].finfo.start_page = -- 2.26.2